Array length reduction should throw in strict mode if it can't delete an element.

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
diff --git a/src/arm/macro-assembler-arm.h b/src/arm/macro-assembler-arm.h
index 4290bc91acf5921d73d2f790b837049b1e065dd0..445c7833176796782764079024889e5ec9ab46af 100644
--- a/src/arm/macro-assembler-arm.h
+++ b/src/arm/macro-assembler-arm.h
@@ -316,7 +316,6 @@ class MacroAssembler: public Assembler {
 
   // Push two registers.  Pushes leftmost register first (to highest address).
   void Push(Register src1, Register src2, Condition cond = al) {
-    DCHECK(!src1.is(src2));
     if (src1.code() > src2.code()) {
       stm(db_w, sp, src1.bit() | src2.bit(), cond);
     } else {
@@ -327,7 +326,6 @@ class MacroAssembler: public Assembler {
 
   // Push three registers.  Pushes leftmost register first (to highest address).
   void Push(Register src1, Register src2, Register src3, Condition cond = al) {
-    DCHECK(!AreAliased(src1, src2, src3));
     if (src1.code() > src2.code()) {
       if (src2.code() > src3.code()) {
         stm(db_w, sp, src1.bit() | src2.bit() | src3.bit(), cond);
@@ -347,7 +345,6 @@ class MacroAssembler: public Assembler {
             Register src3,
             Register src4,
             Condition cond = al) {
-    DCHECK(!AreAliased(src1, src2, src3, src4));
     if (src1.code() > src2.code()) {
       if (src2.code() > src3.code()) {
         if (src3.code() > src4.code()) {
@@ -372,7 +369,6 @@ class MacroAssembler: public Assembler {
   // Push five registers.  Pushes leftmost register first (to highest address).
   void Push(Register src1, Register src2, Register src3, Register src4,
             Register src5, Condition cond = al) {
-    DCHECK(!AreAliased(src1, src2, src3, src4, src5));
     if (src1.code() > src2.code()) {
       if (src2.code() > src3.code()) {
         if (src3.code() > src4.code()) {